Michael Rigby-Jones wrote:

> I'm sure that I've read that any tinitus resulting from exposure to
> loud noise was a sure sign that your hearing had been irreversably
> damaged.  However, I had to take a hearing test a few years back go
> get a track saftey certificate to allow me to work near railway
> tracks.  The doctor who performed this said my hearing was almost
> perfect and much better than normal for my age.

 1}  Like the 99-year-old who smoked all his life.  How much longer
could he have lived if he didn't smoke?  It's called "spread of
characteristics".

 2}  There's loud and there's loud.  A muscle called the stapedius pre-
tensions your eardrum against persistent loud noise.  You can contract
this voluntarily (do you recall doing that?) as well as automatically.
And you move away if the noise really is too loud.  Unexpected
explosions however (track warning detonators?) bypass this.

 3}  There's tinnitus and there's tinnitus.  There's the one you just
notice after the rock concert, and the one that lasts long after the
gunshot.
--
  Cheers,
        Paul B.